1. Field of the Invention
The present invention relates generally to a floatless carburetor including no float chamber and adapted to eject fuel in a suction passage by actuation of a diaphragm. More particularly, the present invention relates to an electronically controlled type floatless carburetor which assures that an adequate air fuel ratio can be obtained within any operational range of an engine.
2. Description of the Prior Art
A floatless carburetor including no float chamber and adapted to eject main fuel and slow system fuel to be described later in a suction passage has been hitherto known. The floatless carburetor is typically constructed such that one wall surface of a fuel regulating chamber is formed by a diaphragm, negative pressure of the suction passage is exerted on the diaphragm via the fuel regulating chamber, and fuel from the fuel regulating chamber is ejected in the suction passage via a main nozzle, a bypass hole and a pilot outlet. Since the floatless carburetor does not include any float chamber, it has an advantage that it can be adapted to any inclined state thereof.
Since the floatless carburetor has a simple structure for ejecting fuel therefrom, an operational range of the engine where an adequate air fuel ratio can be obtained is limitativaly determined. For this reason, the floatless carburetor is used while making a compromise with the fact that an adequate quantity of fuel is not always ejected in various engine operational range as well as in various load range, resulting in an adequate air fuel ratio failing to be obtained.
When the floatless carburetor is used on a ground having a high altitude, since the air fuel ratio is excessively increased with specifications designed for a ground having a low altitude, a measure is taken such that jets and others, i.e., interior components of the carburetor are exchanged with another ones. However, a problem is that many manhours are required for achieving the exchanging operation.